1. Field of the Invention
In one aspect this invention relates to fuel control systems for internal combustion engines. In yet a further aspect this invention relates to a fuel pump system which can recycle fuel to provide anti-vapor lock protection.
2. Prior Art
Normal fuel pump designs provide for fuel to be drawn from the fuel tank which acts as a reservoir and directs the liquid fuel to a device which atomizes the fuel and mixes the fuel with a quantity of air to make a combustible mixture suitable for burning in an internal combustion engine. Under certain circumstances, the fuel in the fuel line is vaporized by the heat present in the engine compartment. When this happens, the fuel pump will not deliver liquid fuel to the fuel atomizing device and the engine will not operate properly.
The vapor lock condition situation generally occurs when the vehicle has been operated for period of time raising the engine compartment temperature to a level which will promote fuel vaporization in the fuel lines physically present in the engine compartment. When vapor lock occurs, the vehicle can not be restarted until the fuel reliquifies or the fuel pump can force liquid fuel to the fuel atomizer. This can be several minutes or even longer. In a civilian application this is extremely irritating and wastes time. In a military situation the danger of an inoperable vehicle is readily apparent.